Breakline Layers¶

The BreaklineLayersConfig file lists the CAD layers whose polylines are treated as surface breaklines. When R3Survey draws strings onto these layers, those polylines force the DTM triangulation to follow the surveyed linework — ensuring contours honour breaks in the surface such as kerb lines, drainage channels, building edges, and retaining walls.

The file is located at: %APPDATA%\SpatialViz\BreaklineLayers\<ConfigName>_BreaklineLayersConfig.txt

Open it from R3MANAGECONFIGS → Edit Breakline Layers.

File format¶

One layer name per line. Lines beginning with # are comments.

# BREAKLINE LAYERS CONFIG
BUILDINGS
DRAINAGE
FENCES
KERB

Layer names are matched case-insensitively.

How it works¶

A breakline is formed between any two contourable points that share a segment on one of the listed layers. The breakline is defined by those two points, constraining the triangulation along the drawn polyline.

For a breakline to be effective:

The polyline must be on a layer listed in this file.
Both endpoints (or intermediate survey points along the polyline) must be contourable — meaning they match a rule in ContourablePointsConfig.
The points must have valid elevations (not removed by DeleteElevation()).

Example (from R3Survey2025 configuration)¶

# BREAKLINE LAYERS CONFIG (R3Survey 2025)
BUILDINGS
BUILDINGS_G
BUILDINGS_LG
C-MARKERS
COMMS
DRAINAGE
EARTH
ELECTRICAL
FENCES
GAS
HARDSTAND
LANDSCAPE
LEVEL
POOLS
RD
RD-KB
SERVICES
SEWER
STREET_FURNITURE
TOPOGRAPHY
VEGETATION
WALLS
WATER

Tips¶

Only list layers whose linework should influence the DTM — omit annotation and label layers
The layer names here correspond to what StringStyleConfig assigns to drawn polylines — keep them consistent
If a layer is listed here but has no contourable points at either end of its segments, it has no effect on the surface
Adding a layer to this file does not create the layer in the drawing — layers must exist in the drawing template